1. Field of the Invention
The present invention relates generally to position sensors and more particularly to a Hall position sensor of the type having a permanent Hall magnet and an analog/digital Hall effect sensing device disposed proximate to the Hall magnet, the Hall position sensor being powered by and sending feedback to an external controller.
2. Prior Art
Hall position sensors are usually deployed as an integral part of closed loop feedback control systems which are used in a variety of fields such as automotive vehicle component testing and manufacturing, semiconductor manufacturing, industrial automation and robotics and the like. A Hall position sensor of this type comprises a Hall magnet (or magnets) disposed in close proximity to an analog or digital Hall effect sensing device which has two input leads for receiving power from an external controller circuit board and one output lead for sending position feedback signal information to the controller. The Hall effect sensing device leads can be surface mounted (soldered) directly to the controller circuit board or when the Hall effect sensing device has to be positioned away from the controller due to packaging problems, the leads are traditionally soldered to wire connectors which connect on the other end to the controller via a special connector or are surface mounted to the board. Using traditional wire connectors is functional but inefficient from a manufacturing point of view as the connection set up involves providing two separate labor intensive physical connections between the Hall effect sensing device and the controller. Also, surface mounting a Hall effect sensing device to the controller circuit board is not always desirable due to possible electromagnetic interference (EMI) from the moving Hall magnet which may interfere with the normal functioning of the controller.
In most applications, the Hall sensing device is usually stationary while the Hall magnet(s) is/are in motion. However, there are certain applications in which it is desirable to have the Hall effect sensing device in motion while the proximate Hall magnet(s) is/are stationary during operation. A moving Hall effect sensing device requires reliable electrical connection to the controller especially in high frequency and/or high cycling applications which cannot be fully achieved with traditional methods which utilize spiral cords or cables with retainer means and the like which are subject to continuous wear and tear during operation. Unreliable electrical connection leads to increased maintenance and troubleshooting costs which is an obvious disadvantage for the cost-conscious manufacturer.
Therefore the need arises for an improved low cost Hall position sensor which is preferably made of inexpensive yet reliable components, is easy to assemble in a matter of seconds and which can provide reliable performance thereby presenting a viable cost-efficient solution for manufacturers. Such an improved Hall position sensor should eliminate the usual wear and tear associated with traditional connections between the Hall effect sensing device and the controller so as to significantly reduce maintenance costs and extend the life of the device in which the Hall position sensor is integrated.
The present invention is directed to an improved Hall position sensor for integrating into a support structure adapted for receiving the same, the Hall position sensor having at least one Hall magnet and communicating with a controller, the improvement comprising at least one Hall effect sensing device disposed proximate to the at least one Hall magnet; and at least one circuit for electrically coupling the at least one Hall effect sensing device to the controller, the at least one circuit having at least one flexible portion for reducing the cost of integrating the Hall position sensor in the support structure.
In accordance with one aspect of the present invention, the at least one circuit is a substantially flexible circuit, the substantially flexible circuit comprising a plurality of flexible electrical conductors embedded between sheets of flexible insulating material. The substantially flexible circuit further comprises first end portion and second end portion, each of the first and second end portions having exposed electrical conductors.
In accordance with another aspect of the present invention, the improved Hall position sensor further comprises means for electrically coupling the first exposed electro-conductive end portion of the substantially flexible circuit to the controller. The coupling means includes a flexible circuit connector on the controller for mating with the first exposed electro-conductive end portion of the substantially flexible circuit.
In accordance with yet another aspect of the present invention, the improved Hall position sensor further comprises means for electrically coupling the second exposed electro-conductive end portion of the substantially flexible circuit to the at least one Hall effect sensing device. The coupling means includes a plurality of electro-conductive leads on the at least one Hall effect sensing device for soldering directly to the second exposed electro-conductive end portion of the substantially flexible circuit.
In accordance with a different aspect of the present invention, a method for reducing the cost of integrating a Hall position sensor into a support structure adapted for receiving the same is disclosed. The Hall position sensor has at least one Hall magnet with the method comprising the steps of providing at least one low cost surface mount Hall effect sensing device with a plurality of electro-conductive leads; disposing the at least one surface mount Hall effect sensing device proximate to the at least one Hall magnet; providing a low cost flexible multiconductor circuit having first end portion and second end portion, each of the first and second end portions having exposed electrical conductors; providing a controller with a flexible circuit connector for mating with the first exposed electro-conductive end portion of the flexible circuit; plugging the first exposed electro-conductive end portion of the flexible circuit in the flexible circuit connector of the controller; and soldering the electro-conductive leads of the at least one surface mount Hall effect sensing device directly to the second exposed electro-conductive end portion of the flexible circuit.
In accordance with a still different aspect of the present invention, a method for reducing the cost of integrating a Hall position sensor into a support structure adapted for receiving the same is disclosed. The Hall position sensor has at least one Hall magnet with the method comprising the steps of providing at least one low cost through hole Hall effect sensing device with a plurality of electro-conductive leads; disposing the at least one through hole Hall effect sensing device proximate to the at least one Hall magnet; providing a low cost flexible multiconductor circuit having first end portion and second end portion, each of the first and second end portions having exposed electrical conductors; providing a controller with a flexible circuit connector for mating with the first exposed electro-conductive end portion of the flexible circuit; plugging the first exposed electro-conductive end portion of the flexible circuit in the flexible circuit connector of the controller; adjusting the length of the electro-conductive leads of the at least one through hole Hall effect sensing device to a length matching the width of the second exposed electro-conductive end portion of the flexible circuit; and soldering the adjusted electro-conductive leads of the at least one through hole Hall effect sensing device directly to the second exposed electro-conductive end portion of the flexible circuit.
These and other aspects of the present invention will become apparent from a review of the accompanying drawings and the following detailed description of the invention.